f, leaving only a slight, whitish scar behind. The total duration
of the disease covers some 20 days in each animal, and owing to the slow
spread of the infection from animal to animal, many weeks may elapse before
a stable can be fully freed from it. The fallen scabs and crusts may retain
their contagious properties for several days when mixed with litter and
bedding upon the floor of the stable, and at any time during this period
they are capable of producing new outbreaks should fresh cattle be brought
into the stalls and thus come into actual contact with them. Again, the
pustules may appear, one after another, on a single animal, in which case
the duration of the disease is materially lengthened.

_Treatment._--In herds of cattle that regularly receive careful handling,
no special treatment will be found necessary beyond the application of
softening and disinfecting agents to such vesicles upon the teats as may
have become ruptured by the hands of the milker. Carbolized vaseline or
iodoform ointment will be found well suited to this work. In more
persistent cases it may be found desirable to use a milking tube in order
to prevent the repeated opening of the pustules during the operation of
milking. Washing the sores twice daily with a weak solution of zinc chlorid
(2-1/2 per cent solution) has been found to assist in checking the
inflammation and to cleanse and heal the parts by its germicidal action.
When the udder is hard, swollen, and painful, support it by a bandage and
foment frequently with hot water. If calves are allowed to suckle the cows
the pustules become confluent, and the ulcerations may extend up into the
teat, causing garget and ruining the whole quarter of the udder.

As young cows are most susceptible to variola, the milker must exercise
constant patience with these affected animals so long as their teats or
udders are sore and tender, else the patient may contract vicious habits
while resisting painful handling. The flow of milk is usually lessened as
soon as the fever becomes established, but is again normal with the return
of perfect health.

The practice of thorough cleanliness in handling or milking affected cattle
may, in many instances, prevent the dissemination of the trouble among the
healthy portion of the herd, but even the greatest care may prove
insufficient to check the spread until it has attacked each animal of the
herd in turn.

ACTINOMYCOSIS (LUMPY JAW)

[Pls. XXXIX-XLI.]